html, body {
	height: 100%;
}

@media only screen and (min-width: 480px) {
	body {
		background: yellow;
	}
}

@media only screen and (min-width: 640px) and (max-width: 1024px) {
	body {
		background: green;
	}
}

@media screen and (min-width: 1024px) {
	body {
		background: blue;
	}
}